1. Field of the Invention
The present invention relates to a slider, and more particularly to a slider for a liner guide.
2. Description of Related Art
A liner guide is mounted between two objects to make the objects smoothly move relative to each other, With reference to FIG. 6, a conventional liner guide comprises a slider and a rail (90). The slider is slidably mounted on the rail (90) and has an inverse U-shaped body (70). Two ball channels (not shown) are respectively defined in each side of the body (70) of the slider, and multiple balls (not shown) are rotatably received in each respective ball channel. Two side covers (80) are respectively attached to two ends of the body (70). An oil channel is defined in each respective side cover (80), such that lubricant oil can be applied to the ball channels through the oil channels in the side covers (80). In addition, a retainer (72) is attached to the body (70) to keep the balls in the ball channels near the bottom of the body (70) from escaping from the corresponding ball channels. With reference to FIGS. 6 and 7, a conventional retainer (72) of the conventional slider has a rectangular frame with two long sides and two short sides. Two tabs (722,724) respectively extend from two short sides of the rectangular frame to engage with the side covers (80). Two hooks (725,726) are formed on the middle portion of the frame, and two holes (728) are defined in the middle portion of the frame. After attaching the retainer (72) to the body (70) of the slider, the long sides of the retainer will face and block parts of openings of the ball channels. Consequently, the openings of the ball channels will be reduced to be smaller than the diameter of the balls, such that the balls will be kept from escaping from the ball channels.
However, with the structure of the conventional of the retainer (72), the retainer (72) cannot be assembled to the body (70) of the slider after the side covers (80) have been assembled to the body (70). The conventional retainer (72) must be simultaneously assembled to the body (70) while the side covers (80) are assembled to the body (70). Therefore, attaching the conventional retainer (72) to the body (70) of the slider is before inserting the balls into the ball channels. To insert the balls into the ball channel through the openings of the ball channel blocked by the retainer (72), the middle portion of the rectangular frame of the retainer (72) must be squeezed to enlarge the openings of the ball channel to allow the balls to pass. Accordingly, a tool extends through the through holes (827) and makes the hooks (725,726) engage with each other, such that the middle portion of the retainer (72) will be deformed so as to enlarge the openings of the ball channels. After the balls have been fed into the ball channel, the hooks (725,726) are released. Therefore, to assemble the conventional slider with a convention retainer (72) is troublesome and difficult.
With reference to FIGS. 6, 8 and 9, the oil channel in each side cover (80) comprises an inlet (83), a branch channel (84), a connecting channel (86), two guiding channels (882) and two connecting holes (884). The inlet (83) is defined in the side cover (80). The branch channel (84) communicates wit h the inlet (83) and has two ends respectively extending to two sides of the side cover (80). Two cavities (82,822) are defined in each respective side of the side cover (80) and respectively communicate with two ball channels in the corresponding side of the body (70). Two guiding cover (88) are attached to the side cover (80) and respectively corresponding to the cavities (82,882). The guiding channels (882) are respectively defined in the guiding covers (88). The guiding channel (882) in the guiding cover (88) corresponding to the first cavity (82) communicates with one end of the branch channel (84), and the guiding channels (882) in the guiding covers (88) communicate with the connecting channel (86). The guiding holes (884) respectively communicate with the cavities (82,82). When lubricant oil is injected from the inlet (83), the lubricant oil will be led into the first cavity (82) through the branch channel (84), the guiding channel (882) and the guiding hole (884) in the corresponding guiding cover (88), and the ball channel communicating with the first cavity (82) will be filled with the lubricant oil. Then, the lubricant oil will be led into the second cavity (822) through the connecting channel (86), the guiding channel (882) and the guiding hole (884) in the corresponding guiding cover (88), and the ball channel communicating with the second cavity (822) will also be filled with the lubricant oil. The lubricant oil can make the slider move on the rail (90) smoothly and keep the balls from wear.
However, the conventional oil channel in the side cover (80) is a serial oil channel. This means that the lubricant must completely fill in the ball channel communicating with the first cavity (82) firstly before the lubricant oil is applied to the ball channel communicating with the second cavity (822). The lubricant oil filling the ball channel communicating with the second cavity (822) is always less then that filling the ball channel communicating with the first cavity (82). This will make the friction between the balls in one ball channel and the rail (90) different from that between the ball in another ball channel and the rail, and this will make unstable movement to the slider. In addition, the wear of the balls in different ball channels is also different, and this will shorten the useful life of the slider.
To overcome the shortcomings, the present invention tends to provide a slider for a liner guide apparatus to mitigate or obviate the aforementioned problems.
The main objective of the invention is to provide a slider for a liner guide and that is easily assembled and has a parallel oil channel system to synchronously feed lubricant oil into all ball channels in the slider. The slider has an inverse U-shaped body, two side covers and a retainer. The body has two sides each having two ball channels. Multiple balls are rotatably received in each respectively ball channel. The side covers are respectively attached to ends of the body and each has an oil channel communicating with the ball channels in the body. The retainer is attached between the side covers and to the bottom of the bridge of the body to keep the balls received in the ball channels near the bottom of the bridge from escaping from the corresponding ball channel. The retainer has a rectangular frame and a resilient hole defined near one end of the rectangular frame to make the rectangular frame have a resilient capability. Consequently, the retainer can be assembled to the body after the balls being inserted into the ball channels in the body, such that to assemble the slider is simplified and easy.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.